Ever notice how everybody is instantly hotter with sunglasses on? It's not because you have some fetish you didn't even know about. It's true for everyone . . . and here's why.

1. They're associated historically with glamor and risk-taking. Which seems kinda obvious, but it wasn't always true. Sunglasses became popular in the 40s, mainly for water and snow sports, and for pilots.

After that, Hollywood stars began wearing them to protect their eyes from camera flashbulbs, so people began to see sunglasses as a glamorous accessory.

2. They make you more mysterious. But not on the superficial level you're thinking about. Basically, you pick up a LOT of information about people when you look them in their eyes.

So if you can't see their eyes, you know less about them . . . and that makes them more intriguing.

3. Most importantly, sunglasses instantly make your face more symmetrical. Even if your face ISN'T. And according to science, facial symmetry is supposedly the universal key to deciding whether someone's face is 'attractive' or not.

Not only are sunglasses symmetrical themselves, but they also hide the asymmetries around your eyes and cheekbones. (New York Magazine's Science of Us)